The present disclosure relates to a feed system that performs non-contact electric power supply (feeding, or power transmission) to a unit to be fed such as an electronic unit. The present disclosure also relates to an electronic unit applied to such a feed system.
In recent years, attention has been given to a feed system (such as a non-contact feed system and a wireless charging system) that performs non-contact electric power supply to a CE device (Consumer Electronics Device) such as a mobile phone and a portable music player. This makes it possible to start charging merely by placing an electronic unit (a secondary-side unit) on a charging tray (a primary-side unit), instead of starting charging by inserting (connecting) a connector of a power-supply such as an AC adapter into the unit. In other words, terminal connection between the electronic unit and the charging tray becomes unnecessary.
Methods of thus performing non-contact power supply are broadly classified into two types of methods. A first method is an electromagnetic induction method that has been already widely known. In this method, a degree of coupling between a power transmission side (a primary side) and a power receiving side (a secondary side) is considerably high and therefore, high-efficiency feeding is possible. A second method is a method called a magnetic resonance method. This method has such a characteristic that a magnetic flux shared by the power transmission side and the power receiving side may be small due to positive utilization of a resonance phenomenon.
Here, such non-contact feed systems are disclosed in WO 00/27531, as well as Japanese Unexamined Patent Application Publication Nos. 2001-102974, 2008-206233, 2002-34169, 2005-110399, and No. 2010-63245, for example.